Pneumatic cylinder (sometimes known as air cylinders) is switch use the power of compressed gas to produce a force in a reciprocating linear motion.
Like hydraulic cylinders, something forces a piston to move in the desired direction. The piston is a disc or cylinder, and the piston rod transfers the force it develops to the object to be moved. Engineers sometimes prefer to use pneumatics because they are quieter, cleaner, and do not require large amounts of space for fluid storage.
Very compact design easy to use large companying force, easy in maintained.